ALSA: usb-audio: Fix unintentional sign extension issue
authorColin Ian King <colin.king@canonical.com>
Thu, 18 Mar 2021 13:20:08 +0000 (13:20 +0000)
committerTakashi Iwai <tiwai@suse.de>
Thu, 18 Mar 2021 13:25:13 +0000 (14:25 +0100)
commit50b1affc891cbc103a2334ce909a026e25f4c84d
treecc54ff2b8d372402beee2fbd11b18e31fc963f00
parentf4df9ee6d7f329d32d756e54f78c084c7e509b24
ALSA: usb-audio: Fix unintentional sign extension issue

The shifting of the u8 integer device by 24 bits to the left will
be promoted to a 32 bit signed int and then sign-extended to a
64 bit unsigned long. In the event that the top bit of device is
set then all then all the upper 32 bits of the unsigned long will
end up as also being set because of the sign-extension. Fix this
by casting device to an unsigned long before the shift.

Addresses-Coverity: ("Unintended sign extension")
Fixes: a07df82c7990 ("ALSA: usb-audio: Add DJM750 to Pioneer mixer quirk")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20210318132008.15266-1-colin.king@canonical.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
sound/usb/mixer_quirks.c